Manufacture of shoes



Jan. 29, 1935. J. CAVANAGH MANUFACTURE OF SHOES Filed July 22, 19,32 2 Sheets-Sheet l Fig. 4.

Jan. 29, 1935. J. CAVANAGH 1,989,080

MANUFACTURE OF SHOES Filed July 22, 1932 2 Sheets-Sheet 2 Fig? ' Avg/m7? atenteci Jan. 2, 1935 rates Application July 22, 1932, Serial No. GZ MDW 12 (Jiainis.

This invention relates to improvements in the manufacture of shoes and is disclosed herein particularly with respect to the treatment of the marginal portions of soles in the manufacture of compo shoes though it should be understood that the invention in some of its aspects is not limited to the treatment of the marginal portions of the soles and is well adapted to use in the manufacture of other types of shoes.

Most compo shoes as manufactured at the present time have their soles attached with pyroxylin cement. The cement is applied ordinarily to the marginal portion of the attaching face of the sole and to the corresponding portion of the shoe bottom. The cement, after it is dry, is activated on the sole or on the shoe bottom or both with a solvent or softener after which the sole is positioned upon the shoe bottom and the shoe and sole placed under pressure and so maintained until the cement has set to an extent sufiicient to make it safe to remove the shoe from the pressure applying device. When the use of pyroxylin cement in this manner for attacking soles to compo shoes first came into extensive commercial use some years ago it was found necessary with the material and equipmerit then available to maintain the shoe and sole under pressure for thirty minutes or thereabouts. It was later recognized that it would be advantageous from the point of view of economical manufacturing and of improved shoemaking to cut down this period, thereby reducing the equipment costs andsaving factory space. Such improvements have been made that it is now 5 practicable to release the shoes from the sole attaching pressure after an interval of not more than a few minutes. This result has been accomplished largely through the use of the cement softeners disclosed in United States Letters Patent No. 1,959,320 and No. 1,959,321, both granted May 15, 1934, on applications filed in the name of Walter H. W edger. By means of these inventions the time which it takes the pyroxylin cement to set has been greatly reduced. However, it remains, and must remain, a fact, regardless of the length of time the cement takes'to set, that the pressure must be maintained until the sole-attaching cement has set sumciently to provide a bond between the sole and the shoe hav- 9 ing a strength great enough to overcome the tendency of the sole to return to the shape which it had before it was applied to the shoe bottom and from which shape it has been forced more or less by the sole-attaching pressure. The tendency of the sole to regain its former shape will depend upon various factors important among which are the amount by which its shape has been changed by the sole attaching pressure and the stiffness, or more accurately the resilience, of the sole material. Even if the soles are molded or conformed to lit the shoe bottom their fit will be only approximate and it still is necessary to maintain the sole-attaching pressure until the cement has set sufficiently to attain a considerable strength.

In the manufacture of other types of shoes the soles are often attached while quite moist or wet and correspondingly soft but this cannot be done when attaching soles with pyroxylin cement since any considerable amount of Water present in the soles will precipitate the pyroxylin from the cement and result in such an insecure sole attachment as to be utterly worthless. Softening compounds of various sorts have been used for treating the sole leather from which the soles used in the manufacture of compo shoes are cut, but such compounds are avoided by the manufacturers of the better grades of shoes by reason oi the belief that they damage the Wearing qualities of the soles. This last, of course, does not apply to certain classes of treatment by which a large amount of oily material is worked into sole leather used in the manufacture of various sport shoes and other shoes intended particularly for outdoor wear; but such soles cannot be used on shoes the soles of which are attached with pyroxylin cement since the very large amount of oily material which they contain prevents the obtaining of a sufiiciently strong sole-attaching bond.

In view of these circumstances it is an object of the present invention further to reduce the period of time during which the sole-attaching pressure need be maintained, regardless of the nature of the cement and/or softener used and of whether the soles are molded or conformed. It is a further object of the invention to do this in a manner which will not detract from the wearing qualities of the shoes.

As illustrated herein this is accomplished by r rendering the marginal portion, but not the central portion, of each sole permanently inert and thereby greatly reducing its tendency to separate from the shoe bottom. This may be done, .with in the scope of the invention, either by a mechanical treatment ,of the marginal portion of the sole, preferably by stretching the fibres over a narrow area substantially parallel to and spaced a short distance from the edge of the sole, or it may be done by treating the marginal but not the central portion of the sole with a suitable softening compound. Since in either case the central portion of the sole, which receives the brunt of the wear, is unaffected, the wearing quality of the shoe is not injured.

Regarded from another point of view the invention contemplates the applying of a tempering material of a nature to render the leather permanently flexible to the attaching surface but not to the tread surface of the sole. This, of course, avoids any staining of the visible tread surface and preserves the original qualities of the leather adjacent to that surface.

In various of its aspects, and as hereinafter claimed, the invention contemplates a sole the marginal portion of which is relatively flexible and inert as compared with its central portion so that its marginal portion yields readily under the sole-attaching pressure and tends to retain the shape which it is thus caused to take, a shoe having such a sole attached thereto, and improvements in methods of treating soles and in methods of manufacturing shoes characterized by such treatment of the marginal portions of the soles.

With the above and other objects in view the invention will now be described with reference to the accompanying drawings and pointed out in the claims.

In the drawings,

Fig. 1 is a perspective view of a leather outsole the. marginal portion of which has been roughened, illustrating the roughened portion at one side of the sole as provided with a coating of pyroxylin cement;

Fig. 2 illustrates a mechanical treatment of the marginal portion of the sole to render the same flexible or inert and at the same time to overcome a curled condition at the margin of the sole often occurring in soles the. marginal portions of the attaching surfaces of which have been coated with pyroxylin cement;

Fig. 3 is a cross-sectional view through the forepart of a sole the marginal portion of the attaching face of which is provided with a coat of pyroxylin cement;

Fig. 4 is a similar view of the same sole after it has been subjected to the treatment illustrated in Fig. 2; I

Fig. 5 illustrates a welted shoe substantially ready for the performance of the characteristic cement sole-attaching operations;

Fig. 6 is a. fragmentary sectional view through the forepart of the shoe illustrated in Fig. 5 after one side of the shoe, with a coat of pyroxylin cement.

It is unnecessary herein to describe in full the details of the assembling and lasting of shoes or the preparation of their bottoms for cement sole attachment. Accordingly, I have illustrated in Figs. 5 and 9 merely two typical shoe constructions adapted for use in this type of work.Thus Fig. 5 illustrates a shoe 10 provided with a welt 12 secured by stitching 14 to the marginal portion of the shoe upper and to a lip or rib of its insole .16, the various operations up to and including the inseam trimming having been performed, for example, as disclosed in an application for Letters Patent of the United States Serial No. 580,781, filed Dec. 14, 1931, in the name of Darius W. Bunker. It should be understood that the shoe bottom will be filled and the sole engaging surface of the welt, as well as the edge surface of the upper and the lip of the insole resulting from the inseam trimming operation, will be roughened and coated with pyroxylin cement, as is usual in the manufacture of welted shoes having cement attached soles. Fig. 9, on the other hand, illustrates a shoe 18 the overlasted marginal portion 20 of the upper of which is secured in lasted relation to the insole 21 at the sides of the shoe by staples 22 which are anchored in the insole stock without passing completely therethrough, being inserted, for example, by a staple side lasting machine of the character disclosed in Letters Patent of the United States No. 1,796,451, granted March 17, 1931, on an application filed in the name of George Goddu. The overlasted marginal portion of the upper at the ends of the shoe may be secured in lasted relation to the insole in any appropriate manner, for example at the toe by pyroxylin cement and at the heel seat by tacks or other suitable fastenings.

The roughening of the overlasted marginal portion 20 for the reception of cement is indicated at 24 by approximately parallel lines and the coating of dry pyroxylin cement is indicated at 25 by stippling at one side of the shoe, it being understood, of course, that the entire roughened portion of the upper will be coated in this fashion.

The sole 26, as shown in Fig. 1, has been prepared for cement attachment in the usual manner by having its marginal portion somewhat reduced in thickness at the forepart and particularly atthe shank, after which it has been roughened over the area 28, indicated by parallel lines, and the roughened area has been coated with pyroxylin cement 30 indicated by stippling and extending, like the roughened area, from approximately the heel breast line forwardly about the toe of the shoe and rearwardly to the heel breast line at the other side of the shoe. cement dries it tends to curl the marginal portion of the sole toward the flesh side, as illustrated in Fig. 3. This is a matter which is of particular consequence in the manufacture of welted shoes having cement-attached soles since it tends to make difiicult the securing of a good cement bond between the edge portion of the shoe upper and the welt. It tends, moreover, to cause the welt to be rolled up against the shoe upper and this is something which it is usually desired to avoid for style purposes in welted shoes. The tendency of the marginal portion of the cement sole to curl is overcome by the treatment illustrated in Fig. 2 and at the same time the marginal portion of the sole is flexed and rendered inert so that its tendency to regain its former shape after the When the sole-attaching pressure is released is much reduced.

This treatment, moreover, causes the central portion of the sole 26 to contact with the shoe bottom, when the sole-attaching pressure is applied, before the marginal portion does and therefore obviates all danger of it being necessary to slide the cemented marginal portions of the sole relatively to the shoe bottom after the two have contacted as would be necessary if the marginal portion of the sole contacted before the central portion with the shoe bottom.

Fig. 2 illustrates the operation upon the marginal portion of the sole of the working parts of a machine of the character disclosed in Letters Patent of the United States No. 1,255,281, granted Feb. 5, 1918, on an application filed in the name of Frank E. Beckman. This machine is provided with a feed roll 40, an edge bending or flexing roll 42, and a molding roll 44 often spoken of, by reason of its shape, as an acorn. The rolls 40 and 42 are mounted on the main shaft of the machine and are spring pressed toward the molding roll 44 which also is power driven. The sole is presented to this machine with its attach- .ing face upward, thereby not only flexing the edge portion of the sole and stretching the fibres of the leather over a narrow area substantially parallel to but spaced a short distance from the edge of the sole without stretching the fibres of the central portion of the sole but also overcom ing the curl imparted by the drying of the cement to the edge portion of the sole. Thus the marginal portion of the sole is rendered flexible and inert so that it tends to retain rather than to depart from any shape into which it is pressed. Accordingly, when the cement is activated and the shoe and sole placed under pressure, for example in a pad box 50 (Fig. '7) of a cement soleattaching machine, the pressure need be maintained for only a short time, for a substantially shorter time than would be necessary if the edge portion of the sole had not been so treated but all other conditions were unchanged.

Instead of treating the marginal portion of th sole mechanically in the fashion just described, that portion of the sole may be softened with a suitable compound. As illustrated in Fig. 8 such a compound is applied to the marginal portion only of the sole 58, either by a hand brush 60, as illustrated in Fig. 8, or by any other suitable implement or machine. This is done before the pyroxylin cement is applied to the sole and either before or after the marginal portion of the sole is reduced if the sole is to be so treated. Preferably, this is done before the roughening operation is performed since the treatment of the softening compound leaves the surface portion of the leather in a condition peculiarly suitable for the roughening operation and entirely obviates the roughening difiiculties sometimes met with in operating upon hard soles having a more or less glazed surface. The softening compound may be applied in this fashion to the marginal portion of the attaching face of the sole in one or several coats and hot or cold. This method of application insures that the central portion of the sole, by which is meant all except the marginal portion, is in no way affected by the compound used and since the bulk of the wear to which the sole is subjected comes on its central portion the wear,- ing qualities of the shoes will not be affected even though the softening compound does somewhat reduce the toughness of the leather. Moreover, since the compound is applied only to the attaching surface of the sole there is no danger of staining the tread surface.

Various compositions may be applied in this manner to render the marginal portion of the sole flexible ,or inert and thereby to reduce substantially the length of time which the sole-attaching pressure may be maintained. A few examples-of these are the following, in which the percentages are given by weight:

Example 1 Per cent Neatsfoot oll 3 Epsom salts 2 Water 94 Example 2 Per cent Sulphonated oil v 5 Common salt 5 'Water 90 Example 3 Per cent Epsom salts 5 Water 95 Example 4 Percent Sulphonated oil 2 /2 Epsom salts 5 Water 92 The sulphonated oil referred to above may be .sulphonated cod oil, sulphonated neatsfoot oil,

or other similar sulphonated oils. The preparation of any of the above mixtures is facilitated by using hot water. This mixture may be applied to the marginal portions of the soles either hot or cold. It will sink in more rapidly if applied hot and time may be saved in that way. After the soles have set some hours or over night a subsequent application or applications may be made, if desired, to obtain a more effective action. A subsequent application, of course, should not be made until the excess water from the earlier application has had a chance to evaporate, though it should be understood that there will be a certain amount of water retained in the marginal portions of the soles though not enough to cause the soles to feel damp to the touch. This treatment renders the treated portion of the leather permanently flexible or inert in which respect it differs from tempering with water, the efiect 'of which is lost as soon as the leather has a chance to dry.

sure is released and, accordingly, permits the release of the sole-attaching pressure after a shorter time than would otherwise be permissible. a

While the mechanical treatment of the marginal portion of soles has been illustrated herein particularly with respect to the manufacture of welted shoes and the chemical treatment particularly with respectto the manufacture of shoes the marginal portion of the sole which is cemented directly to the shoe upper, it should be understood that both treatments are adapted to use in the manufacture of any kind of shoe having cement-attached outsoles, though, as pointed out above, the mechanical treatment has a peculiar utility in the manufacture of welted shoes.

Having thus described my invention what I claim-as new and desire to secure by Letters Patent of the United States is:

1. A leather outsole neither channelled nor grooved the marginal portion of which contains chemicals which render the leather permanently relatively inert and the central portion of which is relatively resilient.

2. A leather outsole neither channelled nor grooved the marginal portion of which has been treated at its attaching surface with a tempering compound of anature to render the leather permanently flexible, which, however, has not been applied to the tread surface of the sole.

3. A leather outsole the marginal portion of which has been treated at its attaching surface with a softening compound of a nature to render the leather permanently flexible, which, however, has not been applied to or permitted to act upon the central portion of the sole nor to reach any part of the tread surface of the sole.

4. That improvement in methods of manufacturing shoes which comprises treating the marginal portion but not the central portion of a leather sole with a tempering material of a nature to render the leather permanently flexible, and cement attaching the sole to a shoe bottom.

5. That improvement in methods of manufacturing shoes which comprises treating the marginal portion of the attaching surface of a leather outsole with a softening compound of a nature to render the leather permanently flexible without applying the compound to or permitting it to act on the central portion nor to reach any part of the tread surface of the sole, and attaching the sole to a shoe bottom.

6. That improvement in methods of manufacturing shoes which comprises treating the marginal portion of the attaching surface of a leather outsole with a softening compound of a nature to render the sole permanently flexible without applying the compound to or permitting it to act on the central portion nor to reach any part of the tread surface of the sole, and attaching the sole to a shoe bottom.

7. That improvement in methods of manufacturing welted shoes which comprises treating the marginal portion of a leather outsole with a tempering material of a nature to render the leather permanently flexible without so treating the central part of the sole and attaching the sole with pyroxylin cement to the welt and to adjacent portions of the bottom of a welted shoe.

8. That improvement in methods of manufacturing shoes which comprises applying a tempering compound of a nature to render the leather permanently inert at the marginal portions but not the central portion of an outsole, and thereafter pressing the sole against and attaching it to a shoe bottom.

9. That improvement in methods of treating soles which comprises applying pyroxylin cement to the marginal portion of the attaching face of a sole, permitting the cement to dry, and thereafter rendering inert the marginal portion but not the central portion of the sole.

10. That improvement in methods of treating soles which comprises applying pyroxylin cement to the marginal portion of a leather sole, and after the cement is dry stretching the leather fibres over a narrow area substantially parallel to but spaced a short distance from the edge of the sole without stretching the fibres of the central portion of the sole.

11. A leather sole a portion of which has been treated at its attaching surface but not at its tread surface with a tempering material of a nature to render the leather permanently flexible.

12. That improvement in methods of manufacturing shoes which comprises treating the attaching surface but not the tread surface of a sole with a tempering material of a nature to render the leather permanently flexible.

JAMES CAVANAGH. 

